title: Nonconvulsive seizures are common in children treated with extracorporeal cardiac life support.
abstract: OBJECTIVE
  The prevalence of electrographic seizures or nonconvulsive status epilepticus and the effect of such seizures in children treated with extracorporeal cardiac life support are not known. We investigated the occurrence of electrographic abnormalities, including asymmetries in amplitude or frequency of the background rhythm and interictal activity in children undergoing extracorporeal cardiac life support and their association with seizures. We compared mortality and radiologic evidence of neurologic injury between patients with seizures and those without seizures.
  
  
  METHODS
  Retrospective review of medical records and the Extracorporeal Life Support Organization database.
  
  
  METHODS
  PICU at a single institution.
  
  
  METHODS
  All pediatric patients up to 18 years old, who had extracorporeal cardiac life support and continuous electroencephalography monitoring between the years 2006 and 2011.
  
  
  METHODS
  None.
  
  
  RESULTS
  Nineteen patients treated with extracorporeal cardiac life support underwent continuous electroencephalography monitoring. Seizures occurred in four patients (21%) and were exclusively nonconvulsive in three patients. Two of these four patients had nonconvulsive status epilepticus. Interictal discharges on electroencephalography were associated with seizures (odds ratio, 19.5 [95% CI, 1.29-292.75]; p = 0.03). Only 50% of the seizures were detected in the first hour of monitoring, whereas all seizures were detected within 24 hours. All patients with seizures had structural abnormalities seen on neuroimaging. Seizures were not significantly associated with increased mortality. To evaluate for ascertainment bias, we compared outcomes between patients who underwent extracorporeal cardiac life support and received continuous electroencephalography monitoring and those patients who underwent extracorporeal cardiac life support during the study period but did not receive electroencephalography (n = 30).
  
  
  CONCLUSIONS
  Seizures are common in children during extracorporeal cardiac life support, and most seizures are nonconvulsive. In patients undergoing extracorporeal cardiac life support, clinical features are unreliable indicators of the presence of seizures. The presence of seizures is suggestive of CNS injury. This study is limited by the exclusion of neonates, a feature of the clinical use of electroencephalography at our institution. Although seizures were not associated with increased mortality, further prospective studies in larger populations are needed to assess the long-term morbidity associated with seizures during extracorporeal cardiac life support.
authors.affiliation: Department of Pediatrics, Ruth D. & Ken M. Davee Pediatric Neurocritical Care Program, Ann and Robert H. Lurie Children's Hospital of Chicago, Northwestern University Feinberg School of Medicine, Chicago, IL, USA.
authors.forename: Juan A
authors.initials: JA
authors.lastname: Piantino
authors.forename: Mark S
authors.initials: MS
authors.lastname: Wainwright
authors.forename: Michele
authors.initials: M
authors.lastname: Grimason
authors.forename: Craig M
authors.initials: CM
authors.lastname: Smith
authors.forename: Elora
authors.initials: E
authors.lastname: Hussain
authors.forename: Dan
authors.initials: D
authors.lastname: Byron
authors.forename: Anthony
authors.initials: A
authors.lastname: Chin
authors.forename: Carl
authors.initials: C
authors.lastname: Backer
authors.forename: Marleta
authors.initials: M
authors.lastname: Reynolds
authors.forename: Joshua
authors.initials: J
authors.lastname: Goldstein
mesh_terms: D000293:Adolescent; D002648:Child; D002675:Child, Preschool; D004569:Electroencephalography; D005112:Extracorporeal Circulation / Q000401:mortality; D005260:Female; D006333:Heart Failure / Q000150:complications / Q000401:mortality / Q000628:therapy*; D006801:Humans; D007223:Infant; D008297:Male; D012131:Respiratory Insufficiency / Q000150:complications / Q000401:mortality / Q000628:therapy*; D012189:Retrospective Studies; D012640:Seizures / Q000175:diagnosis / Q000453:epidemiology / Q000209:etiology*; D016896:Treatment Outcome